Cutting chain



Feb. 1 0, 1948. A, w. MALL 2,435,892

CUTTING CHAIN File d Jan. 7, 1944 I A l 23 l 40 Ill INVENTUR rlRTHt/B M/"IALL ATTURNEY Patented Feb. 10, 1948 CUTTING CHAINLQ' Arthur sW: Mall; iiiliissmoor,':iill',iiassignoxzdzoMall 1:

Tool-sCompan-yagChicago, 111. 133, corpopationao Illinois s:

Applicatiohflanuary =7, 1944;serial' Ndb' 5l7i442 9 Claims; 1 (Cl. 143-7-s-135i f cutting-chain with?improvedqneans' for':prevent;v

ingthe cutting teeth fro'm kicking-up'about theirpivots when engaging the wood'being out Other objects and'advantagesof my invention will 1 become apparent upon eXaminatio'n --of "the following specification and drawing in which-:1

Fig-$ 1 is a fragmentaryview shdwin'g a section of a cutting chain embodyingmy inventiony Figi 2 is a detail-view of-oheof thei'side pieces orconnecting links Figi 3 is a det'ailiiiewmf ne of the 'cutting teeth; and

FigZ-A is a diagrammaticview-showing the action-"which" takes place whehth'e teth" tend to become disassembled? My link toothed'outtingi chain is comprised of a multitudefseparable tethflsomeof which maybe cutting" teeth 2 indsomeof vi hielri may be raker' teeth-"S which function primarily to re-= move the chips severed by the cutting teethi Referring to FigL- 4,Jeachof the teeth of my cutting-- chain are: comprisedof a; cutting portion: 4, a downwardly depending* tonguetporti'on 5 arrarcuate *s'lot i 'eInd-an areuate tail portionz :1 r 'otat= ably receivedih the arouate' slot fi f each sue ceedin' g tooth! The f-r6nt*wa11" of-=ach slot *6 terminates in a oylindri'caliy shaiped pivot post 8 serving as 'a pivot=f-or the" preceding tooth; The side pieces 9 are welded' face to fae on- 501313081136 sides 1 of e'ach tooth by spot-"weldsdesignated at H! ahd l I so as to be rigidly securedthereto Tl'i'' side pieces -9 serve to providesidewalls' for' slot "6'. to prevent 'side play of the tail portions 1 which are received-"in slotfi. 17 The rear wal-l: l=3 of' eachslot 6 eontinuesupwardly beyondthe upper edgeof side: piece9 to form apointed HOS8-ip0rti0I1-'-|4, therfunction zoffzwhi'chv will be hereinafter :de-iscribed. a1

It will r'be IlOtGdithQtiLthG chaini'may be readily. assembled and disassembledrbyi insertirig the tail portion ail "ofueachmtooth? into the2s1ot ii of :each' succeeding" t'oothz andzwhencthefiehain teeth! are; assembleda-into iacontinuous cutting: chain it can? be seen thatitheiftaihportioml can only be With-r1 drawnafromsmiili by .rotatingtthe tail portioml about rits pivot '8 until .the underneatheedgeg 11:

of thetailportionrreaches "a position substantially. as -shown in Fig: 4. Thus while the cutting chain is traveling about tapainof spaced sprocketsrinot shownkzthe :chainzcann'ot :be'come:disassembleds Aiteinthe .eutting'chaimhas-been :operatedon a chafin 'sawingsmaohine-fora" great length! of-ztima; oocasionajllyconez of rbhe' teetirwill'ibreakrandithe; chain :is. throwrrofffinto spaces'xzwhenzthisioccurs most: of ntheeteethi ares likelytgto becemerdisase:

-: sembled andzscatteredrabout'in.variousidirections:

unless tmeanstare :provided :for preventing. this: :I

have providedna' construction.:in1which:theteethi tend toiremaintassembled whengthe cutting chain v breaks during operation=.t:at the .most,'.only avery. small percentagerofftherteeth would IUECOmGQdiS-J assembled upon breakage of the cutting ,chain. Thus ltheibroken.atoothtcouldube readily; replaced with: a new: tooth: andthe' cutting: chain :couldbe quieklyitrained. about a the sprockets: again; By: referring-:to Eigslrl and'zilit will be notedethat thei sidi'pieces 19 arere'longated and the space between: each succeedirigzside:piecevS: is aboutzl /afi (it is significant:toinotewthateachaof Figs. 1, 2, 3, and 4 are -twice actualisizeandxzonsequently the actual distance is tbnlysaboutze. Thesxspace between each' succeeding sid-e'rpiece 9 is controlled by-the swingingsof the .siderpiece :aboutpivot post 8 when the'ucuttingr chain." traveler-about theusprockets; that is, for example, when one of therteethlorfi swings counterclockwise :about tthe pivot 8 ofwe'ach succeeding" tooth; the: side :piece 9 likewiserswings along :with thetoothttbeingmeldedthereto).1 The lower tcorner '2 9 .of the: side: piece-29' barely clears the. end of the.'suceeding-sidepiece 9 as it swings about the axis of the pivot 8. As==previouslypointed outthe: rear=wall of each'slot-fi is provided with an upwardly extending nose l4 which: necessitates v rotation i of the tail; portions] about pivot 8 t'ovthenmaximum limi-tpftherotationias. shownin' Fig.3) 'ibeforeithe tailzportionfl can be withdrawn fromtslot 6. The limit of rotationuof tailspor-tion' 1 aboutthe pivot 8 of :the succeeding tooth is reached when-thes-frontv-swall:22 ofidee pending :tongue 5 engages the; underneath surface. 23 (of the preceding tooth, as: shown-in Rig-a4. .It will also beinoted that (referring to Fig... 3) pivot post:& is providedewitha rectilinearfrontlwall=4ll.i Bysgirawingi an imaginary i diametrical .line from: pointrAl -to pointy afiiian retricallyxopposite from pointzkl it; wiilzbe-noted thatpivot postal is 00mm prised of a circular portion which exceeds a half circle. Likewise referring to Fig. 3, it will be noted that the circular curvature 43 of tail portion I is in excess of a half circle, consequently, when pivot post 8 is assembled within curvature 43, as viewed in Fig. 1, disassembly of pivot post 8 from within the curvature 43 is only possible when it is rotated to the approximate position as shown in Fig. 4. The reason for this is as follows: If the circular portion of the pivot post 8 is made into an imaginary completed circle (as shown by dotted lines in Fig. 3) then front wall 40 forms a chord of said circle. Thus the distance from said chord to the opposite periphery of the circle is less than the diameter of the circle. Likewise the length of the imaginary chord 44 at the entrance of curvature 43 is less than the diameter of curvature 43, however, said chord length is greater than the distance across pivot post 8 heretofore mentioned, consequently, when pivot'post 8 is rotated Within'curvature 43 to the approximate position shown in Fig. 4, then pivot post 8 can be withdrawn through the restricted entrance of curvature 43. I have shown diagrammatically in Fig. 4 how each tooth is assembled into the preceding tooth. Tooth 2 is inserted beneath tooth 3 and moved inwardly as the bottom edge 25 of side piece 9 rides on the corner 26 of the side piece 9 on tooth 3. During this inserting operation the uppermost part of pivot 8 (designated 27) just clears the nose 28 of tail portion 1. Tooth 2 is thus pushed inwardly until front wall 22 of tongue 5 engages the underneath surface 23 of tooth 3, then tooth 2 is moved upwardly at right angles to the inward movement (front wall 22 riding along surface 23) until tooth 2 is in the postion shown in dotted lines in Fig. 4. Then tooth 2 is rotated counter-clockwise until the tail portion 1 of the preceding tooth 3 is inserted within slot 6 of tooth 2.

It can thus be seen that each tooth when assembled to its preceding and succeeding tooth can be disassembled in only one position (as shown in Fig. 4) and then only after a right angular movement is accomplished. Thus when the cutting chain breaks during operation nearly all of the teeth remain assembled. It is significant to note that when tooth 2 begins to disassemble from tooth 3, the side piece 9 tends to cause the teeth to bounce back into their assembled positions. This action only tends to increase the tendency of the teeth to remain assembled when the cutting chain breaks.

The nose portion l4 at the upper end of each slot 6 serves the additional function of preventing sawdust from getting into the slot 6 by deflecting the sawdust into the cavity 34 where it is carried through the kerf until it is expelled at the exit end of the kerf.

Having thus described my invention, what I claim is:

1. A wood cutting chain comprising a plurality of separable teeth linked together to form a continuous flexible chain wherein adjacent teeth are adapted to assume a straight condition and flex to a bent condition, each of said teeth having a downwardly depending tongue portion and an arcuately shaped tail portion, an elongated substantially rectilinear bearing surface extending from the inner wall of said tail portion, each tongue portion continuing upwardly to form a pivot post, the tail portion of each tooth being rotatably mounted on the pivot post of each succeeding tooth, the front wall of each tongue portion being substantially rectilinear and adapted to engage the substantially rectilinear bearing surface of each preceding tooth whereby to limit the rotative movement of one tooth relative to its preceding tooth when the two teeth are moving from the straight condition to the bent condition, the substantially rectilinear bearing surface being greater in length than the length of the substantially rectilinear front wall of each tongue portion.

2. A wood cutting chain as described in claim 1 wherein means are also provided for limiting rotative movement of one tooth relative to its preceding tooth when the two teeth are moving from the bent condition to the straight condition.

3. A tooth for a cutting chain comprising a forward portion, said forward portion comprising a downwardly depending tongue portion, an arcuate wall at'the rear of said tongue portion, an arcuate slot opening into the upper side of the tongue, one wall of said slot continuing circularly to form a pivot post, the circular portion of said pivot post being in excess of a semi-circle, the front wall of said pivot post interrupting the circular portion of said pivot post in the manner of a chordal line, the distance from the front wall of said pivot post to the rear wall of said pivot post, as measured by an imaginary line drawn normally from said front wall through the axis of the pivot post to the said rear wall, being less than the diameter of the circular portion of said pivot post, an arcuate tail portion adapted for mating with the arcuate slot in the forward portion, the front wall of said tail portion having a circular curvature in excess of a semi-circle whereby the distance across the mouth of said curvature is less than the diameter of said curvature, said last distance, however, being greater than the first mentioned distance across the pivot post.

4. A tooth for a cutting chain as described in claim 3 wherein the rear wall of the arcuate slot in the tongue portion continues circularly upwardly to a point and then recedes angularly rearwardly and downwardly to form an acute angularly shaped nose.

5. A tooth-for a cutting chain as described in claim 3 wherein the rear wall of the arcuate slot in the tongue continues upwardly to a point and then recedes angularly rearwardly and downwardly to form an acute angularly shaped nose, a cutting portion having a front wall continuing downwardly and merging with the base of the nose.

6. A tooth for a cutting chain comprising a forward portion, said forward portion including a downwardly depending tongue portion. a slot in the upper region of said tongue portion, one wall of said slot continuing substantially circularly to form a pivot post, the circular portion of said pivot post being in excess of a semi-circle, the front wall of said pivot post interrupting the circular portion of said pivot post in the manner of a chordal line, the distance from the frontwall of said pivot post to the rear wall of said pivot post, as measured by an imaginary line drawn vertically from said front wall through the axis of the pivot post to the said rear wall, being less than the diameter of the circular portion of said pivot post, an arcuate tail portion adapted for mating with the arcuate slot in the forward portion, the front wall of said tail portion having a circular curvature in excess of a semi-circle whereby the distance across the mouth of said curvature is less than the, diameter of said curvature, said last distance, however, being greater than the first mentioned distance across the pivot post.

'7. A tooth for a cutting chain comprising a forward portion including a downwardly depending tongue portion, an arcuate slot opening into the upper side of the tongue, one wall of said slot continuing circularly to form a pivot post, the other wall of said slot continuing upwardly beyond the plane defined by the uppermost part of the pivot post and then receding angularly downwardly whereby to form a pointed nose portion, and an arcuate tail portion adapted for mating with the arcuate slot in the forward portion of a similar tooth, the front wall of said tail portion having a circular curvature in excess of a semicircle leaving an opening with a neck portion narrower than the diameter of the curvature, the pivot post having one transverse dimension greater than the width of the neck and a second transverse dimension less than the width of the neck, both of such dimensions lying in the plane of the link and at an angle with respect to each other.

8. A tooth for a wood-cutting chain as described in claim 7 wherein a pair of elongated side pieces are rigidly secured to opposite sides of the tooth and extend across the walls of the arcuate slot whereby to form side retaining walls for said slot.

9. A tooth for a cutting chain comprising a forward portion including a downwardly projecting tongue portion, an arcuate slot opening into the upward side of the tongue. one wall of said slot continuing circularly to form a pivot post, an arcuate tail portion adapted for mating with the arcuate slot in the forward portion of a similar tooth, the front wall of said tail portion having a circular curvature in excess of a semicircle leaving an opening with a neck portion narrower than the diameter of curvature, the pivot post having one transverse dimension greater than the width of the neck and a second transverse dimension less than the width of the eck, both of such dimensions lying in the plane of the link and at anangle with respect to each other, an upwardly projecting portion disposed between the forward portion and the tail portion and disposed rearwardly of the arcuate slot, and a forward cutting edge on the upwardly projecting portion.

ARTHUR W. MALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,229,597 Farrer June 12, 1917 106,305 Aydelott Aug. 16, 1870 820,452 Waller May 15, 1906 873,666 Gray et a1. Dec. 10, 1907 1,178,362 Wall Apr. 4, 1916 1,412,315 Peters Apr. 11, 1922 

